ᐅ Is a ventilation system now mandatory for new buildings under the 2016 Energy Saving Ordinance?

It is clear that laws and subsidies are effective in enforcing technical measures. However, they do not change mindsets and habits, or do so only very slowly.

Alex, and that is a good thing. Those in Berlin and elsewhere are not here to raise us, but only to ensure safety, law, and order. We can live our lives on our own.

Please get back on topic... KNX can be discussed elsewhere.

Brief regards

stefanc84 schrieb:
Maybe it would be helpful for some if you explained exactly what you see at a glance I claim the statement is incorrect.

I never said that a mechanical ventilation system with heat recovery is mandatory. I wrote that it’s not feasible without one, and this becomes clear when you look at the requirements of the KfW. Hopefully, the different calculation models on the way to an eligible home will be simplified with the introduction of the Building Energy Act.

The original poster wants to build a solid KfW 55 house, but leaves open how they envision the building envelope of their solid new build. Usually, either a wood pellet or biomass heating system, or a heat pump is required. Most people choose a heat pump due to cost, mostly an air-to-water heat pump. This choice alone is not enough to qualify for funding. Additional insulation (including below the slab) must be installed, possibly a solar system for domestic hot water, and not infrequently a better type of masonry unit (in monolithic construction). Planning a basement will raise the costs significantly. After all these measures, the new build becomes so airtight that it would be negligent to do without a mechanical ventilation system with heat recovery. In that case, it makes sense right away to opt for a combination of an air-to-water heat pump plus mechanical ventilation with heat recovery, as it is more cost-effective overall.

I personally would not omit ventilation in a current new build, but I would also not want to build a subsidized KfW house. The effort does not justify the expected savings in operating costs. Users of KfW subsidies tend to overlook that it is not about supporting their personal project or conserving resources, but solely about injecting additional money into the market. The main beneficiaries are manufacturers of insulation materials. The financiers support this hidden economic stimulus because it lowers their liability risk. The sellers benefit because it brings higher commissions.

Anyone who insists on building a KfW 55 house would do well to hire an independent energy consultant—not one brought in on the recommendation of their general contractor or builder. That is the only way to secure KfW 55 certification after construction is completed.

Your KNX topic has been moved and can be found here:
https://www.hausbau-forum.de/threads/hat-knx-Zukunft.18816/